Most learners do not need to fact check the instructor, but do want to see the operations which were run. Those that are curious can run/edit the notebook themselves.
Edit: The JupyterBook ecosystem (https://executablebooks.org/en/latest/gallery/) as an example of what is possible with stored plots/calculations. Most learners are just going to follow along with the material, but being able to optionally play with the data is the super power of the platform with minimal friction.